One more shot from my city park "expedition". Again a very small (3-4 mm) fly species, this time of family Tephritidae.

Tephritidae are called gall flies and fruit flies (although they are not the true fruit flies belonging to family Drosophilidae). There are ca. 5000 species in this family worldwide, with several dozens found in Europe - many quite similar to each other.

The flies are of major importance in agriculture - many species are serious pests damaging crops. For example one species Bactrocera oleae is a monophague feeding only on fruits of olive trees. Some others are used for biological controll of unwanted weeds.

Species of this family are characteristic for their marbled wings (please see the other POV in workshop) and elongated end of the abdomen. I suspect that this is a species belonging to Tephris genus but cannot say that with certainty. These flies need a real specialist to identify them.